Chapter 6. The Open Economy

Transcription

1 Chapter 6 0 IN THIS CHAPTER, YOU WILL LEARN: accounting identities for the open economy the small open economy model what makes it small how the trade balance and exchange rate are determined how policies affect trade balance & exchange rate 1

2 Imports and exports of selected countries, Exports Imports Percent of GDP Australia China Germany Greece S. Korea Mexico United States Turkish Exports and Imports Billion USD Exports Imports

3 In an open economy, spending need not equal output saving need not equal investment 4 Preliminaries d f C C C d f I I I d f G G G EX = exports = foreign spending on domestic goods IM = imports = C f + I f + G f = spending on foreign goods superscripts: d = spending on domestic goods f = spending on foreign goods NX = net exports (a.k.a. the trade balance ) = EX IM 5

4 GDP = expenditure on domestically produced g & s d d d Y C I G EX ( C C f ) ( I I f ) ( G G f ) EX f f f C I G EX ( C I G ) C I G EX IM C I G NX 6 The national income identity in an open economy Y = C + I + G + NX or, NX = Y (C + I + G ) net exports domestic spending output 7

5 Trade surpluses and deficits NX = EX IM = Y (C + I + G ) trade surplus: output > spending and exports > imports Size of the trade surplus = NX trade deficit: spending > output and imports > exports Size of the trade deficit = NX 8 International capital flows Net capital outflow = S I = net outflow of loanable funds = net purchases of foreign assets the country s purchases of foreign assets minus foreign purchases of domestic assets When S > I, country is a net lender When S < I, country is a net borrower 9

6 The link between trade & cap. flows NX = Y (C + I + G ) implies NX = (Y C G ) I = S I trade balance = net capital outflow Thus, a country with a trade deficit (NX < 0) is a net borrower (S < I ). 10 Saving, investment, and the trade balance (US, ) 25% investment 15% Saving, Investment (% of GDP) 20% 15% 10% 5% saving trade balance (right scale) 0% % 5% 0% -5% -10% Trade Balance (% of GDP)

7 Saving and investment balance, ( ) 12 U.S.: The world s largest debtor nation Every year since 1980s: huge trade deficits and net capital inflows, i.e. net borrowing from abroad As of 12/31/2011: U.S. residents owned $21.1 trillion worth of foreign assets Foreigners owned $25.1 trillion worth of U.S. assets U.S. net indebtedness to rest of the world: $4.0 trillion higher than any other country, hence U.S. is the world s largest debtor nation 13

8 Saving and investment in a small open economy An open-economy version of the loanable funds model from Chapter 3. Includes many of the same elements: production function consumption function investment function exogenous policy variables Y Y F ( K, L) C C( Y T ) I I ( r) G G, T T 14 National saving: The supply of loanable funds r S Y C( Y T ) G As in Chapter 3, national saving does not depend on the interest rate S S, I 15

9 Assumptions about capital flows a. domestic & foreign bonds are perfect substitutes (same risk, maturity, etc.) b. perfect capital mobility: no restrictions on international trade in assets c. economy is small: cannot affect the world interest rate, denoted r* a & b imply r = r* c implies r* is exogenous 16 Investment: The demand for loanable funds r r * Investment is still a downward-sloping function of the interest rate, but the exogenous world interest rate determines the country s level of investment. I (r ) I (r* ) S, I 17

10 If the economy were closed the interest rate would adjust to equate investment and saving: r r c S I (r ) I ( r ) S c S, I 18 But in a small open economy the exogenous world interest rate determines investment and the difference between saving and investment determines net capital outflow and net exports r* r r c I 1 NX S I (r ) S, I 19

11 Next, three experiments: 1. Fiscal policy at home 2. Fiscal policy abroad 3. An increase in investment demand (exercise) Fiscal policy at home An increase in G or decrease in T reduces saving. r * r1 NX 2 S 2 S 1 Results: I 0 NX S 0 NX 1 I (r ) I 1 S, I 21

12 NX and the federal budget deficit (% of GDP), % 8% 6% Budget deficit (left scale) 2% 0% 4% 2% -2% 0% -2% Net exports (right scale) -4% -4% % 2. Fiscal policy abroad Expansionary fiscal policy abroad raises the world interest rate. 1 r r * r2 * NX 2 NX 1 S 1 Results: I 0 I (r ) NX I 0 I ( r ) * 2 I ( r ) * 1 S, I 23

13 NOW YOU TRY 3. An increase in investment demand Use the model to determine the impact of an increase in investment demand on NX, S, I, and net capital outflow. r * r I 1 NX 1 S I (r ) 1 S, I 24 ANSWERS 3. An increase in investment demand I > 0, S = 0, net capital outflow and NX fall by the amount I r * r NX 1 NX 2 S I (r ) 2 I (r ) 1 I 1 I 2 S, I 25

14 The nominal exchange rate e = nominal exchange rate, the relative price of domestic currency in terms of foreign currency (e.g. yen per dollar) 26 A few exchange rates, as of 5/24/2012 country Euro area Indonesia Japan Mexico Russia South Africa U.K. exchange rate 0.79 euro/$ 9,437 rupiahs/$ 79.6 yen/$ 14.0 pesos/$ rubles/$ 8.35 rand/$ 0.63 pounds/$

15 The real exchange rate the lowercase Greek letter epsilon ε = real exchange rate, the relative price of domestic goods in terms of foreign goods (e.g. Japanese Big Macs per U.S. Big Mac) 28 Understanding the units of ε ε e P P * (Yen per $) ($ per unit U.S. goods) Yen per unit Japanese goods Yen per unit U.S. goods Yen per unit Japanese goods Units of Japanese goods per unit of U.S. goods 29

16 ~ McZample ~ one good: Big Mac price in Japan: P* = 200 Yen price in USA: P = $2.50 nominal exchange rate e = 120 Yen/$ ε e P P * 120 $ Yen 15. To buy a U.S. Big Mac, someone from Japan would have to pay an amount that could buy 1.5 Japanese Big Macs. 30 Table 6.2 Big Mac Prices and the Exchange Rate: An Application of Purchasing-Power Parity Mankiw: Macroeconomics, Eighth Edition 31 Copyright 2012 by Worth Publishers

17 ε in the real world & our model In the real world: We can think of ε as the relative price of a basket of domestic goods in terms of a basket of foreign goods In our macro model: There s just one good, output. So ε is the relative price of one country s output in terms of the other country s output 32 How NX depends on ε ε U.S. goods become more expensive relative to foreign goods EX, IM NX 33

18 NX (% of GDP) U.S. net exports and the real exchange rate, % 2% 0% -2% -4% -6% Trade-weighted real exchange rate index Net exports (left scale) Index (March 1973 = 100) -8% Turkey Net Exports and Real Exchange Rate NX RER 35

19 The net exports function The net exports function reflects this inverse relationship between NX and ε: NX = NX(ε) 36 The NX curve for the U.S. ε When ε is relatively low, U.S. goods are relatively inexpensive ε 1 so U.S. net exports will be high NX(ε) 0 NX(ε NX 1 ) 37

20 The NX curve for the U.S. ε ε 2 At high enough values of ε, U.S. goods become so expensive that US exports less than it imports NX(ε 2 ) NX(ε) 0 NX 38 How ε is determined The accounting identity says NX = S I We saw earlier how S I is determined: S depends on domestic factors (output, fiscal policy variables, etc.) I is determined by the world interest rate r* So, ε must adjust to ensure NX ( ε ) S I ( r* ) 39

21 How ε is determined Neither S nor I depends on ε, so the net capital outflow curve is vertical. ε S1 I ( r *) ε adjusts to equate NX with net capital outflow, S I. ε 1 NX 1 NX(ε ) NX 40 Interpretation: supply and demand in the foreign exchange market demand: Foreigners need dollars to buy U.S. net exports. ε S1 I ( r *) supply: Net capital outflow (S I ) is the supply of dollars to be invested abroad. ε 1 NX 1 NX(ε ) NX 41

22 Interpretation: supply and demand in the foreign exchange market demand: Negative net capital outflow (S I ) generates the demand for TL by foreigners who want to invest in Turkey. supply: Negative net exports mean Turks who want to buy foreign net exports supply TL (for dollar) ε ε 1 S1 I ( r *) NX(ε ) NX NX 1 42 Next, four experiments: 1. Fiscal policy at home 2. Fiscal policy abroad 3. An increase in investment demand (exercise) 4. Trade policy to restrict imports 43

23 1. Fiscal policy at home A fiscal expansion reduces national saving, net capital outflow, and the supply of dollars in the foreign exchange market causing the real exchange rate to rise and NX to fall. ε ε 2 ε 1 S 2 I ( r *) S1 I ( r *) NX(ε ) NX NX 2 NX Fiscal policy abroad An increase in r* reduces investment, increasing net capital outflow and the supply of dollars in the foreign exchange market ε ε 1 ε 2 S I ( r *) 1 1 S 1 I ( r2* ) NX(ε ) causing the real exchange rate to fall and NX to rise. NX 1 NX 2 NX 45

24 NOW YOU TRY 3. Increase in investment demand Determine the impact of an increase in investment demand on net exports, net capital outflow, and the real exchange rate. ε ε 1 S I 1 1 NX 1 NX(ε ) NX 46 ANSWERS 3. Increase in investment demand An increase in investment reduces net capital outflow and the supply of dollars in the foreign exchange market ε ε 2 ε 1 S 1 I 2 S I 1 1 NX(ε ) causing the real exchange rate to rise and NX to fall. NX 2 NX 1 NX 47

25 4. Trade policy to restrict imports At any given value of ε, an import quota IM NX demand for dollars shifts right ε S I ε 2 ε 1 NX (ε ) 2 Trade policy doesn t affect S or I, so capital flows and the supply of dollars remain fixed. NX 1 NX (ε ) 1 NX Trade policy to restrict imports Results: ε > 0 (demand increase) NX = 0 (supply fixed) IM < 0 (policy) EX < 0 (rise in ε ) ε S I ε 2 ε 1 NX (ε ) 2 NX (ε ) 1 NX NX 1 49

26 The determinants of the nominal exchange rate Start with the expression for the real exchange rate: e P ε P Solve for the nominal exchange rate: e ε * P P * 50 The determinants of the nominal exchange rate So e depends on the real exchange rate and the price levels at home and abroad and we know how each of them is determined: e ε NX ( ε ) S I( r* ) P P * M P * * * L ( r * *, Y ) * M Lr ( *, Y) P 51

27 The determinants of the nominal exchange rate * P e ε P Rewrite this equation in growth rates (see arithmetic tricks for working with percentage changes, Chapter 2 ): * e ε P P ε * * e ε P P ε For a given value of ε, the growth rate of e equals the difference between foreign and domestic inflation rates. 52 Inflation differentials and nominal exchange rates for a cross section of countries % change in nominal exchange rate 8% 6% 4% Mexico Iceland Pakistan 2% U.K. S. Africa 0% Sweden S. Korea -2% Japan Denmark Canada -4% Singapore Australia -6% Switzerland New Zealand -4% -2% 0% 2% 4% 6% 8% inflation differential

28 Purchasing Power Parity (PPP) Two definitions: A doctrine that states that goods must sell at the same (currency-adjusted) price in all countries. The nominal exchange rate adjusts to equalize the cost of a basket of goods across countries. Reasoning: arbitrage, the law of one price 54 Purchasing Power Parity (PPP) PPP: e P = P* Cost of a basket of foreign goods, in foreign currency. Cost of a basket of domestic goods, in foreign currency. Solve for e : Cost of a basket of domestic goods, in domestic currency. e = P*/ P PPP implies that the nominal exchange rate between two countries equals the ratio of the countries price levels. 55

29 Purchasing Power Parity (PPP) If e = P*/P, then * P P P 1 * * ε e P P P and the NX curve is horizontal: ε = 1 ε S I NX Under PPP, changes in (S I ) have no impact on ε or e. NX 56 Figure 6.14 Purchasing-Power Parity Mankiw: Macroeconomics, Eighth Edition 57 Copyright 2012 by Worth Publishers

30 Does PPP hold in the real world? No, for two reasons: 1. International arbitrage not possible. nontraded goods transportation costs 2. Different countries goods not perfect substitutes. Yet, PPP is a useful theory: It s simple & intuitive. In the real world, nominal exchange rates tend toward their PPP values over the long run. 58 CASE STUDY: The Reagan deficits revisited 1970s 1980s actual change closed economy small open economy G T S r no change I no change NX no change ε no change Data: decade averages; all except r and ε are expressed as a percent of GDP; ε is a trade-weighted index.

31 The U.S. as a large open economy So far, we ve learned long-run models for two extreme cases: closed economy (chap. 3) small open economy (chap. 6) A large open economy like the U.S. falls between these two extremes. The results from large open economy analysis are a mixture of the results for the closed & small open economy cases. For example 60 Figure 6.15 How the Net Capital Outflow Depends on the Interest Rate Mankiw: Macroeconomics, Eighth Edition 61 Copyright 2012 by Worth Publishers

32 Figure 6.16 Two Special Cases Mankiw: Macroeconomics, Eighth Edition 62 Copyright 2012 by Worth Publishers Figure 6.17 The Market for Loanable Funds in the Large Open Economy Mankiw: Macroeconomics, Eighth Edition 63 Copyright 2012 by Worth Publishers

33 Figure 6.18 The Market for Foreign-Currency Exchange in the Large Open Economy Mankiw: Macroeconomics, Eighth Edition 64 Copyright 2012 by Worth Publishers Figure 6.19 The Equilibrium in the Large Open Economy Mankiw: Macroeconomics, Eighth Edition 65 Copyright 2012 by Worth Publishers

34 Figure 6.20 A Reduction in National Saving in the Large Open Economy Mankiw: Macroeconomics, Eighth Edition 66 Copyright 2012 by Worth Publishers Figure 6.21 An Increase in Investment Demand in the Large Open Economy Mankiw: Macroeconomics, Eighth Edition 67 Copyright 2012 by Worth Publishers

35 Figure 6.22 An Import Restriction in the Large Open Economy Mankiw: Macroeconomics, Eighth Edition 68 Copyright 2012 by Worth Publishers Figure 6.23 A Fall in the Net Capital Outflow in the Large Open Economy Mankiw: Macroeconomics, Eighth Edition 69 Copyright 2012 by Worth Publishers

36 A fiscal expansion in three models A fiscal expansion causes national saving to fall. The effects of this depend on openness & size: closed economy large open economy small open economy r rises rises, but not as much as in closed economy no change I falls falls, but not as much as in closed economy no change NX no change falls, but not as much as in small open economy falls 70 CHAPTER SUMMARY Net exports the difference between exports and imports a country s output (Y ) and its spending (C + I + G) Net capital outflow equals purchases of foreign assets minus foreign purchases of the country s assets the difference between saving and investment 71

37 CHAPTER SUMMARY National income accounts identities Y = C + I + G + NX trade balance NX = S I net capital outflow Impact of policies on NX NX increases if policy causes S to rise or I to fall NX does not change if policy affects neither S nor I. Example: trade policy 72 CHAPTER SUMMARY Exchange rates nominal: the price of a country s currency in terms of another country s currency real: the price of a country s goods in terms of another country s goods The real exchange rate equals the nominal rate times the ratio of prices of the two countries. 73

38 CHAPTER SUMMARY How the real exchange rate is determined NX depends negatively on the real exchange rate, other things equal The real exchange rate adjusts to equate NX with net capital outflow 74 CHAPTER SUMMARY How the nominal exchange rate is determined e equals the real exchange rate times the country s price level relative to the foreign price level. For a given value of the real exchange rate, the percentage change in the nominal exchange rate equals the difference between the foreign & domestic inflation rates. 75